-stars/ Solar flares happen when magnetic-field loops threading through sunspots get twisted and break, producing massive amounts of radiation that accelerate charged particles into space. The largest one that Sol ever produced in recorded history was on September 1st, 1859, and it was observed by the British astronomer Richard Carrington. Hours later, auroras were seen in tropical latitudes and telegraph lines threw off sparks, even when disconnected from their batteries.
Flares up to 10 million times as energetic as the Carrington event have been occasionally observed in other stars, but these observations have been spotty. NASA=92s Kepler spacecraft has been observing the same patch of sky continuously, and has been looking for changes in brightness in stars, which could possible signal orbiting planets.
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